OBJECTIVE: Camptothecin (CPT) is one of the most promising anticancer drugs but it produces various side effects because of its non-selectivity towards cancer cells. To overcome these adverse effects, we synthesized biotin conjugate of camptothecin, which was linked via a self-immolative disulfide linker (CPT-SS-Biotin).
METHODS: Biotin conjugated camptothecin linked through a disulfide bond was synthesized following schemes, and the structural characterization was carried out. The stability and drug release studies were performed in the presence of glutathione (GSH) while in vitro studies were performed on 4T1 tumor cell lines. In vivo pharmacological investigation was done using an antitumor Wistar rat model.
RESULTS: The stability and drug release studies were performed in the presence of glutathione (GSH), and CPT-SSBiotin was found to be physiologically stable moiety and can only be cleaved in the presence of GSH to release free CPT. The CPT-SS-Biotin showed higher toxicity in the biotin-overexpressing 4T1 tumor cell line with a lower IC50 value (8.44 μM) compared to camptothecin alone (IC50 > 30 μM). CPT-SS-Biotin also showed 10.6% higher cellular uptake by cells in comparison to free camptothecin. The CPT-SS-Biotin was delivered to cells by binding to the biotin receptors on the cell surface, followed by energy-dependent endocytosis and internalization to cause cellular toxicity.
CONCLUSION: In-vivo tumor suppression studies and in vitro cell line studies along with serological parameters and histopathological studies showed that conjugate produced a high therapeutic effect and remarkably reduced toxic effects in comparison to free CPT. The results suggested that biotinylation of camptothecin via disulfide linker can be a safe and efficacious method in cancer therapeutics.
MATERIALS AND METHODS: Here we reported the initial experience of aflibercept / FOLFIRI in combination. We evaluated treatment-related adverse events (AEs), progression-free survival (PFS) and overall survival (OS).
RESULTS: The majority of the patients experienced gastrointestinal toxicity (grade 1-2), with diarrhea (52%), mucositis (52%), and nausea/vomiting (20%) being largely observed. Neutropenia (16%) and febrile neutropenia (8%) were common grade 3-4 hematological events. Aflibercept-related toxicity was managed as per practice guidelines. No grade 5 event was reported. Median PFS was 6.12 months (95% CI, 4.80-7.20) and OS was 12 months (95% CI, 9.80-14.18). The partial response (PR), stable disease (SD), and progressive disease (PD) rates were 25% (95% CI: 23.4-27.0), 37.5% (95% CI: 31.6-43.3), and 37.5% (95% CI: 22.5-52.5), respectively.
CONCLUSIONS: Aflibercept/FOLFIRI can be administered safely in a second line setting to Malaysian patients with mCRC, as the AEs experienced were generally reversible and manageable. The safety and efficacy outcomes were consistent with those observed in Western populations.
PATIENTS AND METHODS: APEC was a nonrandomized phase 2 trial conducted in the Asia-Pacific region. Patients (n = 289) received once-every-2-weeks cetuximab with investigator's choice of chemotherapy (FOLFOX or FOLFIRI). The primary end point was best confirmed overall response rate (BORR); progression-free survival (PFS) and overall survival (OS) were secondary end points. Early tumor shrinkage (ETS) and depth of response (DpR) were also evaluated.
RESULTS: In the KRAS wt population, BORR was 58.8%, median PFS 11.1 months, and median OS 26.8 months. Expanded RAS mutational analysis revealed that patients with RAS wt mCRC had better outcomes (BORR = 64.7%; median PFS = 13.0 months; median OS = 28.4 months). The data suggest that ETS and DpR may be associated with survival outcomes in the RAS wt population. Although this study was not designed to formally assess differences in outcome between treatment subgroups, efficacy results appeared similar for patients treated with FOLFOX and FOLFIRI. There were no new safety findings; in particular, grade 3/4 skin reactions were within clinical expectations.
CONCLUSION: The observed activity and safety profile is similar to that reported in prior first-line pivotal studies involving weekly cetuximab, suggesting once-every-2-weeks cetuximab is effective and tolerable as first-line therapy and may represent an alternative to weekly administration.
METHODS: OPTIM1SE was a prospective, open-label, observational study. Patients with untreated KRAS wild-type mCRC and distant metastases were treated per locally approved labels and monitored for 3 years via electronic medical records. The primary endpoint was the overall response rate (ORR). Secondary endpoints included safety, progression-free survival (PFS), and overall survival (OS).
RESULTS: From November 19, 2013, to June 30, 2016, 520 patients were enrolled in 51 sites. Patients were mostly male (61.2%), with a mean age of 58.5 (±12.0) years; 420 patients received leucovorin, 5-FU, and irinotecan-based regimens and 94 received leucovorin, 5-FU, and oxaliplatin. The most common primary tumor site was the rectum (38.8%), with liver metastases (65.0%). ORR was 45.4% (95% CI, 41.1%-49.7%), including 26 patients (5.0%) with a complete response. Median PFS was 9.9 months (95% CI, 8.2-11.0); median OS (mOS) was 30.8 months (95% CI, 27.9-33.6). Higher mOS was associated with tumors of left compared with right-sided origin (hazard ratio, 0.69 [95% CI, 0.49-0.99]); higher ORR was also associated with liver metastases compared with all other metastases (55.4% vs. 40.2%). Adverse events were consistent with the known safety profile of cetuximab.
CONCLUSION: Cetuximab-based 5-FU regimens were effective first-line treatments for mCRC in routine practice, particularly in patients with left-sided disease and liver metastases only.